and me, in NZ, trying to tell a friend exactly when the launch window opened: 12:00 UTC on 2023-04-17 translates to midnight on the night between 17/4/2023 and 18/4/2023 NZ time. I ended up telling the friend that the window opened 00:01 2023-04-18 NZT, because that got rid of the 00:00 ambiguity